The Challenge

To provide the maximum range and flying time, the aircraft are fitted with cabin-mounted, cased-bladder type fuel tanks. The replacement sensor had to fit and install in the existing aperture, which required a lightweight, robust sensor designed for an inverted installation and fully sealed to prevent any fuel leaking through the sensor.

The sensors also had to be available on short delivery lead times to fit in with the availability of the aircraft in their flight programmes for maintenance work.

The Results

Using solid-state capacitive level sensor technology, a solution developed to meet the mechanical installation and product reliability characteristics was confirmed.

A custom design was produced with a 5-hole mounting flange with integral 'O'-ring seal. A fully sealed and potted internal construction ensured no fuel leak paths were possible in its inverted installation orientation. A military specification 6-pin connector guaranteed reliable and secure connection.

With a probe length of just under 1 metre, additional mechanical features were included to enhance the mechanical integrity and reliability of the sensor. Due to the tight timescales involved, the customer took responsibility for the flight approvals process under their '21 Step' procedure.

Project results and benefits

Provision of a solution providing required reliability performance

Development of a custom sensor

Mechanical enhancement for longer probe length

Mil-spec connector for reliability and security

Lightweight, solid-state design with no moving parts

Delivery to aircraft availability schedules

Step by step: Phases of working with the customer

Receipt of inquiry and confirmation of product suitability

Development of design incorporating the requirements of the customer's specification

Drawings and CAD models submitted to customer for verification and approval

On receipt of approval, first production quantities supplied for initial aircraft

After successful fitting, integration and testing, manufacture of sensors for the remaining fleet